The present invention generally relates to redundancy systems for improving reliability in communications equipment, and more particularly to a unique microwave configuration which is especially suitable for enhancing the reliability of multiple beam communications satellites.
It has been the practice to provide communications satellites with one redundant travelling wave tube (TWT) amplifier for each active amplifier in a parallel redundancy configuration. Communications satellites have been launched which have microwave configurations employing one redundant amplifier for each two active amplifiers. These satellites typically contain a relatively small number of limited bandwidth antenna beams with multiple channelized amplifiers for example, the INTELSAT IV-A per beam. In either of these configurations, a successful end of life for the communications satellite required that only three-fourths of the channels function using either the primary of redundant TWT amplifiers.
Future communications satellites will employ a large number of full bandwidth multiple antenna beams. Moreover, operational constraints placed on these satellites result in the requirement that all beams must function at the end of the life of the satellite. The net result is a requirement for approximately two orders of magnitude improvement in the reliability of the individual TWT amplifier units using presently known redundancy configurations. The possibility of achieving this kind of an improvement in the reliability of individual TWT amplifier units is remote.